Signalsmith-Audio/basics
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Damping and high/low cuts

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Geraint 2022-12-05 22:59:56 +00:00
parent 713f3a309a
commit a5c32ecaf8
2 changed files with 76 additions and 14 deletions
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84
reverb.h
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@ -5,6 +5,7 @@ Released under the Boost Software License (see LICENSE.txt) */
#include "dsp/delay.h"
#include "dsp/mix.h"
#include "dsp/filters.h"
SIGNALSMITH_DSP_VERSION_CHECK(1, 3, 3)
#include "./stfx-library.h"
@ -25,9 +26,12 @@ namespace signalsmith { namespace basics {
ParamRange dry{1}, wet{0.5};
ParamRange roomMs{80};
ParamRange rt20{1};
ParamRange early{1};
ParamRange early{1.5};
ParamRange detune{2};
ParamRange lowCutHz{80}, highCutHz{12000};
ParamRange lowDampRate{1.5}, highDampRate{2.5};
ReverbSTFX(double maxRoomMs=200, double detuneDepthMs=2) : maxRoomMs(maxRoomMs), detuneDepthMs(detuneDepthMs) {}
template<class Storage>
@ -35,8 +39,8 @@ namespace signalsmith { namespace basics {
using namespace signalsmith::units;
storage.info("[Basics] Reverb", "An FDN reverb");
int version = storage.version(4);
if (version != 4) return;
int version = storage.version(5);
if (version != 5) return;
storage.param("dry", dry)
.info("dry", "dry signal gain")
@ -74,6 +78,25 @@ namespace signalsmith { namespace basics {
.info("detune", "Detuning rate (inside feedback loop)")
.range(0, 5, 50)
.unit("", 1);
storage.param("lowCutHz", lowCutHz)
.info("low cut", "Removes low frequencies")
.range(10, 80, 500)
.unit("Hz", 0);
storage.param("lowDampRate", lowDampRate)
.info("low damp", "Reduce low frequencies over time")
.range(1, 2, 10)
.unit("", 1);
storage.param("highCutHz", highCutHz)
.info("high cut", "Removes high frequencies")
.range(1000, 5000, 20000)
.unit("kHz", 1, kHzToHz, hzToKHz, 1000, 1e100)
.unit("Hz", 0);
storage.param("highDampRate", highDampRate)
.info("high damp", "Reduce high frequencies over time")
.range(1, 2, 10)
.unit("", 1);
}
template<class Config>
@ -89,7 +112,7 @@ namespace signalsmith { namespace basics {
delay2.configure(maxRoomSamples, 1);
delay3.configure(maxRoomSamples, 0.5);
delay4.configure(maxRoomSamples, 0.25);
delayFeedback.configure(maxRoomSamples*1.36 + detuneDepthSamples, 1);
delayFeedback.configure(maxRoomSamples*1.5 + detuneDepthSamples, 1);
delayEarly.configure(maxRoomSamples, 0.25);
}
@ -100,6 +123,11 @@ namespace signalsmith { namespace basics {
delayFeedback.reset();
delayEarly.reset();
for (auto &f : lowCutFilters) f.reset();
for (auto &f : highCutFilters) f.reset();
for (auto &f : lowDampFilters) f.reset();
for (auto &f : highDampFilters) f.reset();
detuneLfoPhase = 0;
}
@ -116,7 +144,12 @@ namespace signalsmith { namespace basics {
auto &&inputRight = io.input[1];
auto &&outputLeft = io.output[0];
auto &&outputRight = io.output[1];
block.setupFade([&](){
updateDelays(roomMs.to()*0.001*config.sampleRate);
});
bool fading = block.fading();
auto smoothedDryGain = block.smooth(dry);
Sample scalingFactor = stereoMixer.scalingFactor2()*0.015625; // 4 Hadamard mixes
auto smoothedWetGain = block.smooth(wet.from(), wet.to());
@ -126,22 +159,19 @@ namespace signalsmith { namespace basics {
double decayGainTo = dbToGain(getDecayDb(rt20.to(), roomMs.to()));
auto smoothedDecayGain = block.smooth(decayGainFrom, decayGainTo);
auto smoothedInputGain = block.smooth( // scale according to the number of expected echoes in the first 100ms
scalingFactor*std::sqrt((1 - decayGainFrom)/(1 - std::pow(decayGainFrom, 100/roomMs.from()))),
scalingFactor*std::sqrt((1 - decayGainTo)/(1 - std::pow(decayGainTo, 100/roomMs.to())))
2*scalingFactor*std::sqrt((1 - decayGainFrom)/(1 - std::pow(decayGainFrom, 100/roomMs.from()))),
2*scalingFactor*std::sqrt((1 - decayGainTo)/(1 - std::pow(decayGainTo, 100/roomMs.to())))
);
auto smoothedEarlyGain = block.smooth(early, [&](double g) {
return g*0.35; // tuned by ear
});
block.setupFade([&](){
updateDelays(roomMs.to()*0.001*config.sampleRate);
});
bool fading = block.fading();
updateFilters(config.sampleRate, decayGainTo);
// Detuning LFO rate
double detuneCentsPerLoop = detune*std::sqrt(roomMs*0.001);
double detuneLfoRate = (detuneCentsPerLoop*0.0004)/detuneDepthSamples; // tuned by ear, assuming 3/8 channels are detuned
for (int i = 0; i < block.length; ++i) {
Sample inputGain = smoothedInputGain.at(i);
Sample decayGain = smoothedDecayGain.at(i);
@ -170,6 +200,9 @@ namespace signalsmith { namespace basics {
Array feedback = delayFeedback.readDetuned(lfoArray, fade);
Householder::inPlace(feedback);
for (int c = 0; c < 8; ++c) {
feedback[c] = highDampFilters[c](lowDampFilters[c](feedback[c]));
}
Array feedbackInput;
for (int c = 0; c < 8; ++c) {
int c2 = (c + 3)&7;
@ -190,8 +223,11 @@ namespace signalsmith { namespace basics {
samples = delay2.write(samples).read();
Hadamard::unscaledInPlace(samples);
Array feedback = delayFeedback.readDetuned(lfoArray, lfoSin);
Array feedback = delayFeedback.readDetuned(lfoArray);
Householder::inPlace(feedback);
for (int c = 0; c < 8; ++c) {
feedback[c] = highDampFilters[c](lowDampFilters[c](feedback[c]));
}
Array feedbackInput;
for (int c = 0; c < 8; ++c) {
int c2 = (c + 3)&7;
@ -210,6 +246,10 @@ namespace signalsmith { namespace basics {
std::array<Sample, 2> stereoOut;
stereoMixer.multiToStereo(samples, stereoOut);
for (int c = 0; c < 2; ++c) {
stereoOut[c] = highCutFilters[c](lowCutFilters[c](stereoOut[c]));
}
Sample dryGain = smoothedDryGain.at(i);
Sample wetGain = smoothedWetGain.at(i);
@ -226,6 +266,22 @@ namespace signalsmith { namespace basics {
double detuneLfoPhase = 0;
double detuneDepthSamples = 0;
using Filter = signalsmith::filters::BiquadStatic<Sample>;
std::array<Filter, 2> lowCutFilters, highCutFilters;
std::array<Filter, 8> lowDampFilters, highDampFilters;
void updateFilters(Sample sampleRate, Sample feedbackGain) {
for (auto &f : lowCutFilters) f.highpassQ(lowCutHz/sampleRate, 0.5);
for (auto &f : highCutFilters) f.lowpassQ(highCutHz/sampleRate, 0.5);
Sample lowDampHz = lowCutHz + 100;
Sample highDampHz = highCutHz*0.5;
Sample lowDampGain = std::max(std::pow(feedbackGain, lowDampRate), 1e-3);
Sample highDampGain = std::max(std::pow(feedbackGain, highDampRate), 1e-3);
for (auto &f : lowDampFilters) f.lowShelf(lowDampHz, lowDampGain, Filter::defaultQ);
for (auto &f : highDampFilters) f.highShelf(highDampHz, highDampGain, Filter::defaultQ);
}
static Sample getDecayDb(Sample rt20, Sample loopMs) {
Sample dbPerSecond = -20/rt20;
Sample secondsPerLoop = loopMs*Sample(0.001);

6
units.h
View File

@ -19,6 +19,12 @@ namespace signalsmith { namespace units {
static double ratioToPc(double linear) {
return linear*100;
}
static double kHzToHz(double kHz) {
return kHz*1000;
}
static double hzToKHz(double hz) {
return hz*0.001;
}
}} // namespace
#endif // include guard